1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Copyright (C) 2017 Álvaro Fernández Rojas <noltari@gmail.com>
4 */
5
6 #include <common.h>
7 #include <dm.h>
8 #include <errno.h>
9 #include <led.h>
10 #include <log.h>
11 #include <asm/io.h>
12 #include <dm/lists.h>
13 #include <linux/delay.h>
14
15 #define LEDS_MAX 32
16 #define LEDS_WAIT 100
17
18 /* LED Mode register */
19 #define LED_MODE_REG 0x0
20 #define LED_MODE_OFF 0
21 #define LED_MODE_ON 1
22 #define LED_MODE_MASK 1
23
24 /* LED Control register */
25 #define LED_CTRL_REG 0x4
26 #define LED_CTRL_CLK_MASK 0x3
27 #define LED_CTRL_CLK_1 0
28 #define LED_CTRL_CLK_2 1
29 #define LED_CTRL_CLK_4 2
30 #define LED_CTRL_CLK_8 3
31 #define LED_CTRL_POL_SHIFT 2
32 #define LED_CTRL_POL_MASK (1 << LED_CTRL_POL_SHIFT)
33 #define LED_CTRL_BUSY_SHIFT 3
34 #define LED_CTRL_BUSY_MASK (1 << LED_CTRL_BUSY_SHIFT)
35
36 struct bcm6358_led_priv {
37 void __iomem *regs;
38 uint8_t pin;
39 bool active_low;
40 };
41
bcm6358_led_busy(void __iomem * regs)42 static void bcm6358_led_busy(void __iomem *regs)
43 {
44 while (readl_be(regs + LED_CTRL_REG) & LED_CTRL_BUSY_MASK)
45 udelay(LEDS_WAIT);
46 }
47
bcm6358_led_get_mode(struct bcm6358_led_priv * priv)48 static unsigned long bcm6358_led_get_mode(struct bcm6358_led_priv *priv)
49 {
50 bcm6358_led_busy(priv->regs);
51
52 return (readl_be(priv->regs + LED_MODE_REG) >> priv->pin) &
53 LED_MODE_MASK;
54 }
55
bcm6358_led_set_mode(struct bcm6358_led_priv * priv,uint8_t mode)56 static int bcm6358_led_set_mode(struct bcm6358_led_priv *priv, uint8_t mode)
57 {
58 bcm6358_led_busy(priv->regs);
59
60 clrsetbits_be32(priv->regs + LED_MODE_REG,
61 (LED_MODE_MASK << priv->pin),
62 (mode << priv->pin));
63
64 return 0;
65 }
66
bcm6358_led_get_state(struct udevice * dev)67 static enum led_state_t bcm6358_led_get_state(struct udevice *dev)
68 {
69 struct bcm6358_led_priv *priv = dev_get_priv(dev);
70 enum led_state_t state = LEDST_OFF;
71
72 switch (bcm6358_led_get_mode(priv)) {
73 case LED_MODE_OFF:
74 state = (priv->active_low ? LEDST_ON : LEDST_OFF);
75 break;
76 case LED_MODE_ON:
77 state = (priv->active_low ? LEDST_OFF : LEDST_ON);
78 break;
79 }
80
81 return state;
82 }
83
bcm6358_led_set_state(struct udevice * dev,enum led_state_t state)84 static int bcm6358_led_set_state(struct udevice *dev, enum led_state_t state)
85 {
86 struct bcm6358_led_priv *priv = dev_get_priv(dev);
87 unsigned long mode;
88
89 switch (state) {
90 case LEDST_OFF:
91 mode = (priv->active_low ? LED_MODE_ON : LED_MODE_OFF);
92 break;
93 case LEDST_ON:
94 mode = (priv->active_low ? LED_MODE_OFF : LED_MODE_ON);
95 break;
96 case LEDST_TOGGLE:
97 if (bcm6358_led_get_state(dev) == LEDST_OFF)
98 return bcm6358_led_set_state(dev, LEDST_ON);
99 else
100 return bcm6358_led_set_state(dev, LEDST_OFF);
101 break;
102 default:
103 return -ENOSYS;
104 }
105
106 return bcm6358_led_set_mode(priv, mode);
107 }
108
109 static const struct led_ops bcm6358_led_ops = {
110 .get_state = bcm6358_led_get_state,
111 .set_state = bcm6358_led_set_state,
112 };
113
bcm6358_led_probe(struct udevice * dev)114 static int bcm6358_led_probe(struct udevice *dev)
115 {
116 struct led_uc_plat *uc_plat = dev_get_uclass_plat(dev);
117
118 /* Top-level LED node */
119 if (!uc_plat->label) {
120 void __iomem *regs;
121 unsigned int clk_div;
122 u32 set_bits = 0;
123
124 regs = dev_remap_addr(dev);
125 if (!regs)
126 return -EINVAL;
127
128 if (dev_read_bool(dev, "brcm,clk-dat-low"))
129 set_bits |= LED_CTRL_POL_MASK;
130 clk_div = dev_read_u32_default(dev, "brcm,clk-div",
131 LED_CTRL_CLK_1);
132 switch (clk_div) {
133 case 8:
134 set_bits |= LED_CTRL_CLK_8;
135 break;
136 case 4:
137 set_bits |= LED_CTRL_CLK_4;
138 break;
139 case 2:
140 set_bits |= LED_CTRL_CLK_2;
141 break;
142 default:
143 set_bits |= LED_CTRL_CLK_1;
144 break;
145 }
146
147 bcm6358_led_busy(regs);
148 clrsetbits_be32(regs + LED_CTRL_REG,
149 LED_CTRL_POL_MASK | LED_CTRL_CLK_MASK,
150 set_bits);
151 } else {
152 struct bcm6358_led_priv *priv = dev_get_priv(dev);
153 unsigned int pin;
154
155 priv->regs = dev_remap_addr(dev);
156 if (!priv->regs)
157 return -EINVAL;
158
159 pin = dev_read_u32_default(dev, "reg", LEDS_MAX);
160 if (pin >= LEDS_MAX)
161 return -EINVAL;
162
163 priv->pin = pin;
164
165 if (dev_read_bool(dev, "active-low"))
166 priv->active_low = true;
167 }
168
169 return 0;
170 }
171
bcm6358_led_bind(struct udevice * parent)172 static int bcm6358_led_bind(struct udevice *parent)
173 {
174 ofnode node;
175
176 dev_for_each_subnode(node, parent) {
177 struct led_uc_plat *uc_plat;
178 struct udevice *dev;
179 const char *label;
180 int ret;
181
182 label = ofnode_read_string(node, "label");
183 if (!label) {
184 debug("%s: node %s has no label\n", __func__,
185 ofnode_get_name(node));
186 return -EINVAL;
187 }
188
189 ret = device_bind_driver_to_node(parent, "bcm6358-led",
190 ofnode_get_name(node),
191 node, &dev);
192 if (ret)
193 return ret;
194
195 uc_plat = dev_get_uclass_plat(dev);
196 uc_plat->label = label;
197 }
198
199 return 0;
200 }
201
202 static const struct udevice_id bcm6358_led_ids[] = {
203 { .compatible = "brcm,bcm6358-leds" },
204 { /* sentinel */ }
205 };
206
207 U_BOOT_DRIVER(bcm6358_led) = {
208 .name = "bcm6358-led",
209 .id = UCLASS_LED,
210 .of_match = bcm6358_led_ids,
211 .bind = bcm6358_led_bind,
212 .probe = bcm6358_led_probe,
213 .priv_auto = sizeof(struct bcm6358_led_priv),
214 .ops = &bcm6358_led_ops,
215 };
216